#ifndef _WX_LAYOUT_H_
#define _WX_LAYOUT_H_

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

#include "wx/object.h"

// X stupidly defines these in X.h
#ifdef Above
#undef Above
#endif
#ifdef Below
#undef Below
#endif

#if wxUSE_CONSTRAINTS

// ----------------------------------------------------------------------------
// forward declrations
// ----------------------------------------------------------------------------

class wxWindowBase;
class wxLayoutConstraints;

// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------

#define wxLAYOUT_DEFAULT_MARGIN 0

enum wxEdge {
  wxLeft, wxTop, wxRight, wxBottom, wxWidth, wxHeight,
  wxCentre, wxCenter = wxCentre, wxCentreX, wxCentreY
};

enum wxRelationship {
  wxUnconstrained = 0,
  wxAsIs,
  wxPercentOf,
  wxAbove,
  wxBelow,
  wxLeftOf,
  wxRightOf,
  wxSameAs,
  wxAbsolute
};

// ----------------------------------------------------------------------------
// wxIndividualLayoutConstraint: a constraint on window position
// ----------------------------------------------------------------------------

class wxIndividualLayoutConstraint : public wxObject {
  public:
    wxIndividualLayoutConstraint();

    // note that default copy ctor and assignment operators are ok

    virtual ~wxIndividualLayoutConstraint() {}

    void Set( wxRelationship rel, wxWindowBase *otherW, wxEdge otherE, int val = 0, int marg = wxLAYOUT_DEFAULT_MARGIN );

    //
    // Sibling relationships
    //
    void LeftOf( wxWindowBase *sibling, int marg = wxLAYOUT_DEFAULT_MARGIN );
    void RightOf( wxWindowBase *sibling, int marg = wxLAYOUT_DEFAULT_MARGIN );
    void Above( wxWindowBase *sibling, int marg = wxLAYOUT_DEFAULT_MARGIN );
    void Below( wxWindowBase *sibling, int marg = wxLAYOUT_DEFAULT_MARGIN );

    //
    // 'Same edge' alignment
    //
    void SameAs( wxWindowBase *otherW, wxEdge edge, int marg = wxLAYOUT_DEFAULT_MARGIN );

    // The edge is a percentage of the other window's edge
    void PercentOf( wxWindowBase *otherW, wxEdge wh, int per );

    //
    // Edge has absolute value
    //
    void Absolute( int val );

    //
    // Dimension is unconstrained
    //
    void Unconstrained() { relationship = wxUnconstrained; }

    //
    // Dimension is 'as is' (use current size settings)
    //
    void AsIs() { relationship = wxAsIs; }

    //
    // Accessors
    //
    wxWindowBase *GetOtherWindow() { return otherWin; }
    wxEdge GetMyEdge() const { return myEdge; }
    void SetEdge( wxEdge which ) { myEdge = which; }
    void SetValue( int v ) { value = v; }
    int GetMargin() { return margin; }
    void SetMargin( int m ) { margin = m; }
    int GetValue() const { return value; }
    int GetPercent() const { return percent; }
    int GetOtherEdge() const { return otherEdge; }
    bool GetDone() const { return done; }
    void SetDone( bool d ) { done = d; }
    wxRelationship GetRelationship() { return relationship; }
    void SetRelationship( wxRelationship r ) { relationship = r; }

    // Reset constraint if it mentions otherWin
    bool ResetIfWin( wxWindowBase *otherW );

    // Try to satisfy constraint
    bool SatisfyConstraint( wxLayoutConstraints *constraints, wxWindowBase *win );

    // Get the value of this edge or dimension, or if this
    // is not determinable, -1.
    int GetEdge( wxEdge which, wxWindowBase *thisWin, wxWindowBase *other ) const;

  protected:
    // To be allowed to modify the internal variables
    friend class wxIndividualLayoutConstraint_Serialize;

    // 'This' window is the parent or sibling of otherWin
    wxWindowBase *otherWin;

    wxEdge myEdge;
    wxRelationship relationship;
    int margin;
    int value;
    int percent;
    wxEdge otherEdge;
    bool done;

    DECLARE_DYNAMIC_CLASS( wxIndividualLayoutConstraint )
};

// ----------------------------------------------------------------------------
// wxLayoutConstraints: the complete set of constraints for a window
// ----------------------------------------------------------------------------

class wxLayoutConstraints : public wxObject {
  public:
    // Edge constraints
    wxIndividualLayoutConstraint left;
    wxIndividualLayoutConstraint top;
    wxIndividualLayoutConstraint right;
    wxIndividualLayoutConstraint bottom;
    // Size constraints
    wxIndividualLayoutConstraint width;
    wxIndividualLayoutConstraint height;
    // Centre constraints
    wxIndividualLayoutConstraint centreX;
    wxIndividualLayoutConstraint centreY;

    wxLayoutConstraints();

    // note that default copy ctor and assignment operators are ok

    virtual ~wxLayoutConstraints() {}

    bool SatisfyConstraints( wxWindowBase *win, int *noChanges );
    bool AreSatisfied() const {
      return left.GetDone() && top.GetDone() &&
             width.GetDone() && height.GetDone();
    }

    DECLARE_DYNAMIC_CLASS( wxLayoutConstraints )
};

#endif // wxUSE_CONSTRAINTS

#endif // _WX_LAYOUT_H_
